Changes of Compound Muscle Action Potential in Short-term Steroid Therapy for Compression Injury of Rat Sciatic Nerve

Purpose: Many surgical procedures in oral and maxillofacial area can induce trauma to the peripheral nerve. The aim of the study is to evaluate the effects of short-term steroid therapy on nerve recovery after crush injury. Methods: Sixteen rats were randomly divided into two groups. The right sciatic nerves were exposed, crushed, and sutured. The control group was not given steroids. The test group was injected with dexamethasone disodium phosphate (2 mg/kg body weight/day) for 7 days. In all animals, compound muscle action potential (CMAP) was recorded before and at 1, 7, 14, 21, and 28 days after injury. Results: The amplitude of the CMAP before and at 1, 7, 14, 21, and 28 days after injury were $53.20{\pm}4.80$ mV, $20.12{\pm}5.38$ mV, $30.01{\pm}14.15$ mV, $31.14{\pm}13.56$ mV, $31.73{\pm}16.33$ mV, and $37.23{\pm}16.98$ mV in the control group, and $55.25{\pm}6.72$ mV, $18.62{\pm}6.26$ mV, $29.50{\pm}13.06$ mV, $32.90{\pm}13.226$ mV, $30.17{\pm}11.80$ mV, and $38.41{\pm}12.27$ mV in the test group, respectively. The nerve conduction velocity was $18.82{\pm}3.94$ m/s, $16.73{\pm}3.48$ m/s, $19.60{\pm}2.45$ m/s, $18.68{\pm}3.94$ m/s, $18.02{\pm}3.51$ m/s, and $19.25{\pm}3.88$ m/s in the control group, and $18.94{\pm}3.48$ m/s, $17.28{\pm}2.53$ m/s, $7.57{\pm}2.54$ m/s, $18.77{\pm}2.12$ m/s, $19.48{\pm}1.55$ m/s, and $19.22{\pm}2.97$ m/s in the test group, respectively. There was no significant difference between both groups (P>0.05). Conclusion: This study did not show any therapeutic effect of short-term administration of steroids on injured rat sciatic nerve. Further studies are needed.

백서 좌골신경의 압박손상에 대한 단기간 스테로이드 투여 시 복합근활동전위의 변화